1. Field of the Invention
The present invention relates to a method of testing a print head, a printing method, a device for testing a print head, and a printer.
2. Description of the Related Art
In a print head in which recording elements are arranged in a line form or a matrix form, if there is an abnormality in the recording elements, image quality defects occur in an image to be printed. For example, in an inkjet type of print head (a liquid (ink) containing a coloring material and a functional material is separated into droplets, and discharged toward a recording target (medium) according to an image signal (print signal) so that the coloring material and the functional material are attached and transferred to the medium), if there is an abnormality such as non-discharge or a discharge direction defect in a nozzle that is the recording element, image defects such as a streak or unevenness occur in an image to be printed.
As a method of testing a state of each recording element included in a print head, a method of testing a state of each recording element by printing a test chart is known. Further, as a method of testing a state of each recording element during execution of a printing job, a method of testing a state of each recording element at any time by printing a test chart in a margin region of paper is known.
JP2014-4736A describes a method of testing a state of each nozzle during execution of a printing job in an ink jet printer that performs color printing using four colors of ink of ink including cyan, magenta, yellow, and black. According to the method described in JP2014-4736A, colors of ink for printing the test chart are switched for each paper, and states of the nozzles are sequentially tested for each color of ink. That is, JP2014-4736A describes a method for testing states of the nozzles sequentially on a certain group basis by switching a combination of nozzles that print a test chart on each paper. According to this method, there is an advantage that a region (a margin region of the paper) necessary to print the test chart can be narrowed. Further, there is an advantage that the amount of data to be processed in one test can be reduced and high-speed processing can be achieved.